Specific amounts of water for growing.

[OmegaVermelho]

You always water for the size of the plant, not the size of the pot.

I allways water for the size of the pot .... why???As long as im sure that drainage is good, the time between waterings will be longer and the work of carrrying lots of water will happen less frequently...also i´m not saying that if i have plants in 3 gallon pots i´ll water them with 3 gallons i´m just saying that the size of the pot is my reference...also i find that since i started using this method the plants roots have grown not only across the areas where usually water and air pockets can be found but in a very well distributed scructure all around the pot...i do this NO MATHER THE SIZE OF THE PLANT!!!!!!!!!!.....but when i say this i allways add......POTS MUST HAVE EXCELLENT DRAINAGE!!!!!!!!...and of course that many other stuff is related to the watering issue...heat, humidity, airflow bla bla bla have a huge impact on a how u should water ur plant...imo u just need to pay atention to the plants, before all this high tech grow gear that we have today the growers had no more that the knowledge of experience and they did just fine....well im :stoned: :stoned: so ill check back later to find out more about what goin on in the water world..Peace and Pot

[Dutch Pimp]

....I used a cheap 4 dollar..moisture meter...water- when dry reading shows...don't water again..until another dry reading shows...I follow the K.I.S.S. principle

[babystarbud]

i fully agree with letting them dry out a bit.
i have however quoted on another thread that my seedlings are taking between 30-50ml twice daily...they are in small pots under an HPS and dry out fast....the pots wigh pretty much nothing when i water them.

watering really is just somthing that you get a feel for, the more you grow.
everyones heat/drainage/soil(retention)/plants will be different so, to say that a plant/pot thats a certain size needs "x" ammount of water daily isnt really a very good guide.

moisture meters are a really good idea, i use one myself now and then or just to double check, but after a while i can just tell, its like a sixth sence that developes lol

[MegaOctane12]

That sounds much more reliable and less likely to give you moss growing on the top of the soil medium.

I've always understood that having a consistantly wet medium is a BAD thing, for seedlings, vegging plants and flower.. If anything as the plant grows you spread the watering out even more.. going from 4 or 5 waterings a week down to two or even one watering a week with a larger plant.

The larger the plant, the more water it's going to be absorbing.

Watering so that water comes out of the bottom of the pot would also ensure that the roots are growing down and using as much of the soil medium as possible.

A consistantly wet soil medium with seedlings can cause what's known as "damping-off".

Bob.

Hi Bob, can you clarify this for me... Watering the plant until it comes out the bottom takes Microorganisms and nutrients out of the medium. So in your opinion, what benefit does this serve?


Wet and dry cycles are very over rated in my opinion, because there is a certain amount of oxygen in the water your applying, albeit making up 1% of plants needs. Take for example Tranobles grow, he water's a certain amount that varies according to the plants life cycle. He dosen't flood and drain the soil from what I remember. He gets fantastic results, granted the room is sealed. Just like to hear some technical/scientific arguments why wet and dry cycles are better than precise amounts. Although water logging is a bad thing, I don't see the importance of trying to mimic outdoor conditions, seeing as all other conditions are subject to the growers intervention. I think that if you take some Hydrophonics systems as an example, the root ball can sustain themselves in water almost completely submerged without being suffocated. I think its a fallacy to assume that you can drown roots in a soil medium because the soil just is not saturated enough to devoid the medium of oxygen. You would have to water log the entire medium consistently to kill the roots.

[BobBong]

Hi Bob, can you clarify this for me... Watering the plant until it comes out the bottom takes Microorganisms and nutrients out of the medium. So in your opinion, what benefit does this serve?


Wet and dry cycles are very over rated in my opinion, because there is a certain amount of oxygen in the water your applying, albeit making up 1% of plants needs. Take for example Tranobles grow, he water's a certain amount that varies according to the plants life cycle. He dosen't flood and drain the soil from what I remember. He gets fantastic results, granted the room is sealed. Just like to hear some technical/scientific arguments why wet and dry cycles are better than precise amounts. Although water logging is a bad thing, I don't see the importance of trying to mimic outdoor conditions, seeing as all other conditions are subject to the growers intervention. I think that if you take some Hydrophonics systems as an example, the root ball can sustain themselves in water almost completely submerged without being suffocated. I think its a fallacy to assume that you can drown roots in a soil medium because the soil just is not saturated enough to devoid the medium of oxygen. You would have to water log the entire medium consistently to kill the roots.

With hydro do you not use an air stone?

The idea of watering until it comes out the bottom ensures that the roots will be growing down to the bottom of the pot, using as much of the soil medium as possible for the root ball. It also ensures that the nutrients you add will saturate the soil and fully feed the plant.
Also, by the act of percolation the built up salts will head to the bottom of the pot making it that much easier to flush them out when the time comes.

In reality you CAN water any plant a specific amount of water, as long as the roots are getting what they need, the humidty of the medium isn't maintained at a high level and the ambient humidity isn't affected.
Generally, this involves leaving a few days between each watering to allow for the water to at least begin to dry up.
You do however want to promote the growth of the roots to the bottom of the soil so that the rootball is larger.

Interesting opinions on this. Non are really wrong.. but it is best to know what is needed when watering our plants.

[MegaOctane12]

Thanks for that Bob. I've come to the conclusion that wet and dry cycles are probaly the safest and easiest option, although I haven't found too much scientific information to suggest that measured dosage is more beneficial. I'd thought I'd post this because I found it interesting and its for anyone else who wants to know.

Plants, obviously as a by product of photosynthesis produce oxygen so that they have relatively easy access to oxygen during the daylight cycle. The roots on the other hand have a much harder time to utilise enough oxygen for their requirements. This results in restricting root respiration, which in turn slows photosynthesis, which in turn reduces the growth of the plant. Consequently, the happiness and the potential of the plant are very dependant uopn the roots securing enough oxygen. Plants are only able to grow as well as the roots allow it ; yeild can be directly measured in proportion to the root growth. Warm water holds directly less oxygen than the cold water, however, very cold water can be detrimental to the plants, effectively, shocking the root system until the water warms up enough for the plants to get over this shock. The colder and fresher the water, the more oxygen content ; the warmer, the less. Approximatly 0.0014% of dissolved oxygen can be found in very cold, fresh water. Approximately 0.0008% of dissolved oxygen can be found in fresh water at room temperature and water at room temperature is exactly how the plants like it. Heating your water too much can be very detrimental to your plants potential.

Oxygen obtained via the roots directly from the nutrient solutin only makes up 1% of the plants needs. So oxygen supplied via the nutrient solution is only a minor source supplied to the roots. Aerating the nutrient solution will help, however, this mainly serves to kill off any pathogens, basically keeping the nutrient fresher for longer. So you can see that allowing the plants some dry time will server to get more air to the roots. Even in aerophonics, which delivers a highly oxygenated solution directly to the rootball, it is essential to give plants dry time (at night for example) to allow air to reach the root system. Another tequnique is to add H202 to the reservoir, which again , due to its extra oxygen atom, increases the dissolved oxygen in the reservoir. However, when H202 is diluted, it becomes unstable and soon breaks down and dissolves completely into the reservoir, so it normally will only oxygenate the reservoir for a few hours. Also, when H202 is regularly administered to the reservoir, it keeps the nutrient solution fresher for longer. However, overdoing H202 can be very detrimental to the plant's roots. In high doses, it attacks many usable food chains that the plant will be deprived of.


Highly oxygenated root systems benefit from another very important fact. Oxygen manipulates and effects the electrical charge found in water and for that fact, nutrients. This changes in electrical charges allows roots to uptake water and nutrients with a lot less energy compared to non-oxygenated root systems, so clearly roots benefit from as much oxygen as you can provide them. Properly aerated solutions will absorb up to 0.0008% oxygen and hold it for up to 24 hours.

Share the Knowledge

[Pezzo]

thanx 4 the info but i thought plants used up co2 and gave out oxygen so feedin it co2 would be more benificial wouldnt it?

[BobBong]

thanx 4 the info but i thought plants used up co2 and gave out oxygen so feedin it co2 would be more benificial wouldnt it?

Co2 can only be used in HID lighting and generally requires an enclosed , relatively airtight area so that you can raise the Co2: o2 ratio. However, this is only needed if you have an enclosed area with high concentrations of o2 (or a lot of plants).

Co2 is only utilized properly by advanced growers who know what they're doing.

[Pezzo]

a lot of plants - like 10 plants ina 3'sq area?

[BobBong]

a lot of plants - like 10 plants ina 3'sq area?

And airtight? ... yea.. something like that. You basically would have enough Co2 in the air simply by living in the same house as the plants. If the grow room is airtight.. well, that's different.